To determine how many boxes of cookies Emilio had at the start of business on Monday, we need to evaluate the function given. The function provided is [tex]\( x + y = 42 \)[/tex].
In this function:
- [tex]\( x \)[/tex] represents the number of hours since he opened the bakery.
- [tex]\( y \)[/tex] represents the number of boxes of cookies remaining in the bakery.
We need to find out the initial number of boxes, which corresponds to when Emilio just opens the bakery. At that moment, the number of hours since opening, [tex]\( x \)[/tex], is 0 (because the bakery has just opened).
To find [tex]\( y \)[/tex] when [tex]\( x = 0 \)[/tex]:
[tex]\[ x + y = 42 \][/tex]
Substitute [tex]\( x = 0 \)[/tex] into the equation:
[tex]\[ 0 + y = 42 \][/tex]
Simplify the equation:
[tex]\[ y = 42 \][/tex]
Thus, at the start of business on Monday, Emilio had [tex]\( 42 \)[/tex] boxes of cookies.
So, the correct answer is:
C. 42
